Heat-insulating material and process of producing the same.



. OMPOSITIONS,

COATING R PLASTIC.

gal

UNITED STATES OFFICE.

HAROLD S. asrrnnn pggsg; OF CHICAGO, ILLINOIS, ASSIGNOR OF FOUR-FIFTHS TO AMES 3'. REYNOLDS, OF CHICAGO, ILLINOIS.

A Examiner 1/ HEAT-INSULATING MATERIAL AND PROCESS OF PRODUCING THE SAME.

1,230,085. I Specification ofLetters Patent. Patented J 11119 12, 1917,

No Drawing. Application filed October 30, 1916. Serial No. 128,433.

To all whom it may concern; this cellular structure would act as an insu- I Be it known that I, HAROLD S. ASHEN- lating element, but the material of my inven- HURST, a citizen of the United States, and tion combines the qualities of heat insularesident of Chicago, in the county of Cook tlon, lightness, cheapness and stability as to 5 and State of Illinois, have invented certain form under extreme heat. The material is new and useful Improvements in Heat-Inlargely composed of a substance heretofore sulating Material and Processes of Producconsidered as useless, inasmuch as no use ing the Same, of which the following is a therefor, as far as I am aware, had been specification. found. I utilize the asbestos recovered from 10 My invention relates to a new and useful the waste of asbestos mills. The asbestos composition of matter, and has particular thus recovere 1 comminuted condition, reference to a material adapted for use in no fiber being apparent; in fact, a fibrous many situations and more specially as a heat asbestos does not lend itself to the producs insulating material. This application is a tion of the most desirable form of the mate- 5 continuation of my application Serial No. rial. Although asbestos is considered to be 60,683, filed November 10, 1915, in so far as the most desirable of any of the refractory the disclosures thereof are identical. materials for the present use, a desirable ma- Materials which are substantially imperterial can be produced by employing other 'vious to the transference of heat units, or refractory materlals, 2911. 85. calcium 20 which are, in other words, poor conductors sulfate pr kiesel uhr. With t 1s m .of heat, are required in many locations, as, mnmuminum which in the for instance, in the covering of steam or hot presenceo vwa er reac s W1 carbonate of water pipes, as insulation in the wallsfof calcium wlth the evolution of car on 10x1 refrigerators and biilildiilngsl,1 etc. it perfeipt mg to the reaction 25 insulatin materia s on com ine t e qualities of lightness, resistance to extreme AI2(SO")3+ZIC H O+3CO heat and stability of form or composition 6 4 2 under such extremes of heat. To these qualihe proportlons preferably employed are .ties should be added cheapness in cost of s stantlally as follows: 'llhirtyrtwopar s 30 rodu ti I i of the refractor material. e gl ijgparts of t e I have produced a new composition of $13 a e a PM. .9. ecarbonatee matter which combines the qualities just 'proportlons, of course, Winn ormentioned, as well as many other qualities der to Vary the structure of the material de- 7 Q- t f d t A t ial roduc d in aesired. For instance, if it is desirable to form 35 cordance with the directions given herein, the material with a more pronounced celluf may, if desired, be cast-in place, such use lar structure; that is, wherein the spaces thereof being contemplated in the construcare larger, the quantlty of the sulfate, and tion of buildings, or as' an adjunct thereto. consequently of carbon d1ox1d, is increased.

1 i The material when located in the walls of a In some instances, it may be desirable that 4 building acts as a sound deadener and as a the material should set or harden more heat insulator in addition to being absoquickly, 1n WhlCh case I may add a quantity 95, lutely fireproof. The material, when formed of laster of Paris (substantially anhy- .as hereinafter directed, has a specific gravity dro'us calcium sulmk It will be underi of substantially 0.4, which is substantially stood. that these varlatlons 1n the materials;

45 that of white pine and only slightly greater and in the proportlons of materials will rethan that of cork. This will give an idea of sult in a variation in the Specific gravities of its extreme lightness. It will be understood, the resulting products. In some ilstances therefore, that the substance, when formed the specific gravity may be as hi as 1,

:3 as directed, is very porous or sponge-like in although for all practical commercial pur- 50 character; each of the multitude of spaces, poses it wlll be much less than that.

which are in the form of cells, acts as a dead In pract1ce the materials referred to will air space, with the result that its insulating ,be mixed in their dry state, in which condlv effect is little short of remarkable. I am tion the compound is inert and may be kept ii. aware, of course, that any material having such condition'as long as desired. The

materials being finely divided, a given weight thereof will occupy but a relatively small space. When, however, the insulating material is to be formed, a quantity of water is added, sufficient to form a paste, whereupon reaction begins, releasing a quantity of carbon dioxid which forms a multitude of cells in the gelatinous felty structure comprised of aluminum hydrate and asbestos, and materially increasing the size thereof. The reaction referred to will be complete within a short time and the calcium sulfate which is formed will take on its additional molecule of water and set so that the substance will become hard and rigid in the maintenance of its form, even under extreme heat, no change in appearance, or form, having been found to take place at a temperature v of 3000 degrees F. As stated, after having become hardened, the material is very light, a cubic foot thereof weighing in the neighborhood oftwenty-five pounds. After the substance has been mixed with water it may be poured into a mold for walls, floors or ceilings of a building, or within the walls of a refrigerator, or it may be cast around furnaces or steam pipes, or it may be cast in molds and applied to these locations by other means. By a series of tests, it has been found that the insulating value of this'substance is greater than that of any other substance known to applicant. Primarily this substance is composed of magnesium silicate (asbestos), calcium carbonate and'aluminuni sulfate. The physical peculiarities of the composition are distinct from those of its primary constituents as follows: It is light without sacrificing strength, stable in air and of a peculiar spongy texture, each small void consisting of an individual cell more or less distinct from one another. Its reaction is nearly neutral, showing only a trace of alkalinity.

Its formation is due to direct interaction of the acid reacting sulfate of aluminum with calcium carbonate in the presence of an excess of water. This interaction results in the liberating of carbon dioxid, which exerts a leavening action on the mass, causing it to rise like a bread sponge. At the same time this rising occurs, there is formed a hydrate of aluminum (Al OH (which either partially or wholly is in the form of a gelatinous colloidal salt) and sulfate of calcium (CaSO this calcium sulfate takes on a molecule of water, thereby hydraulically setting. As there ispresent a quantity of finely divided asbestos, this results in toughening the mass by forming a felty substance with the aluminum hydroxid and the calcium sulfate. It is this felty mass which becomes inflated with carbon dioxid (CO thus forming the innumerable cells found throughout the finished product.

The chemical process involv d progresses hvdrat rythmically as shown by the following equations:

This progressive formula may be expressed in its entirety as From its peculiar physical constitution this compound will combine the insulating properties of asbestos and dead air, each and every individual cell acting as an individual insulator.

It is possible that a method can be found whereby other sulfates, as for example ferrous sulfate zincsulfate pr-W m cxenaeemarnqxwe a in num sulfate or all of it. If, however, these sulfatesartefis'dittv'dll be necessary to add a quantity of sulfuric acid to the solution of sulfates together \v1tl ,,a ,,.col1oi5 l, sucl1.as

' This-1s necessary y e a ove enumerated sulfates have not suflicient cohesion to form a felty mass, as aluminum sulfate has.

Obviously the exact proportion referred to need not be strictly followed in order to secure a desirable result. Other variations in the composition may also be made and I do not, therefore, wish to be limite except as indicated by the scope of my claims.

I claim:

1. A new composition of matter in the form of a solid, having a distinctly cellular structure and containing a silicate in the form of asbestos as the major constituent, aluminum hydrate and calcium sulfate, substantially as described.

2. A new composition of matter in the form of a cellular solid body having a specific gravity of substantially .4 and contaming a silicate in the form of asbestos as the major constituent, aluminum hydrate and calcium sulfate, substantially as described.

3. A new composition of matter havin a distinctly cellular structure and a specific gravity less than 1 and composed principally of finely divided asbestos and calcium sulfate.

4. A composition of matter having a pronounced cellular structure and a specific gravity less than 1 and composed of asbes tos in a comminuted conditlon and a substance which hydraulically sets following the reaction by which the cellular structure is formed.

5. A composition of matter having a pronounced cellular structure and a specific gravity less than 1 and composed of asbestos in a comminuted condition, aluminum nd a substance which hydrauli- COMPOSITIONS,

COATING 0R PLASTIC.

cally sets following the reaction by which the cellular structure is formed.

6. The process of forming a cellular insulating material having a specific gravity less than 1 and which is insoluble and highly refractory, which consists in combining in the presence of water a silicate in a finely divided condition, and a plurality of substances, the combmation of which cause a reaction whereby a gas is released, the mass is expanded by the gas and a multitude of cells is formed therein, and which mass later hydraulically sets, substantially as described.

7. The process of forming a cellular insulating material which consists in combining in the presence of water substantially Examiner thirty-two parts of a silicate which is inert in the subsequent reaction and which substance forms the major constituent of the final product, eight parts of a salt having HAROLD S. ASHENHURST.

Witnesses:

H. C. JAooBs, T. D. Bu'rmn.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

